Safety envelope



Aug. 15, 1944. o. v. LALONDE SAFETY ENVELOPE Filed June 17, 1943 INVENTOR 05am MLALO/VDE Patented Aug. 15, 1944 SAFETY ENVELOPE Oscar V. Lalonde, New York, N. Y., assignor to Cushman & DenisonManufacturing Company,

Inc., New York, N. Y.,

Iork

a corporation of New Application June 17, 1943, Serial No. 491,092

2 Claims. (01. 229-450) This invention relatesto what are called safety envelopes, meaning envelopes which when once closed and sealed cannot be penetrated by mechanical means without destruction of envelope material, and which cannot be surreptitiously opened by such means as steaming or the like, without leaving a permanent tell-tale.

Among the objects of the invention are to pro-- vide a device of this kind which is easy and cheap to manufacture, comprising preferably a single piece of paper or the like material; to provide in the construction of the device for the actual destruction of a part of the envelope in case opening of the sealed envelope as by steaming is attempted; to provide in addition a'tell-tale visible from the outside of a closed envelope that has been tampered with, such tell-tale becoming visible as a result of the fraudulent steaming or heat treatment or the like; and to provide guard portions at the several corners of the envelope to discourage attempts to penetrate the envelope at those points by insertion and manipulation of a small tool such as tweezers or the like.

Other objects and aims of the invention, more or less broad than those stated above, Will be evident from the following specification taken in connection with the drawing forming a part thereof.

In the drawing:

Fig. 1 is a plan view of the blank from which an envelope embodying the invention is formed, the dotted lines indicating the lines of fold;

Fig. 2 is an elevation looking at the envelope formed up from the blank of Fig. 1, closed and sealed;

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 2; in both Figs. 2 and 3 no contents are shown within the envelope;

Fig. 4 is a detailed sectional view showing the relation of the side and bottom flaps of the completed envelope, and of the openings therein for the visual tell-tale, and of the manner in which the sealing tongue forming part of the upper flap of the envelope is entered into the envelope through said openings;

Fig. 5 is a view showing part of the subjectmatter of Fig. 1, partly broken away, and illustrating a modified form of comb-flap, with the right-hand main flap, and its attached combfiap, partly folded in, but neither one sealed in place; and

Fig. 6 is a view in perspective, with parts broken away, showing the guard folds at one of the corners of the envelope.

Referring to the numerals on the drawing, the

blank shown in Fig. 1, of paper or other suit-'- able material, comprises a body portion 1 rectangular in form, and provided with a bottom flap 8, a side fiap 9 (being the one on the left of Fig. 1), a side flap l0, and a top or sealing flap ll.

At each corner of the body portion there is a triangle I2, defined as to two sides of the triangle by extensions of the horizontal and vertical boundary lines of rectangular body I intersecting at such corner, and as to the third side of the triangle by a line joining the ends of such extensions. Preferably the extensions of the horizontal boundary lines of the rectangle are longer than those of the vertical boundary lines of the rectangle, and the hypotenuse of the triangle joins one of the side flaps to the sealing flap II or to the bottom flap 8, as the case may be. The horizontal and vertical boundary lines of rectangle -l, and their extensions, constitute the lines of fold for the blank in forming-it up into an envelope, with the triangles I2 in their cornerprotecting position as hereinafter described.

Each of the side flaps and the bottom flap is provided with an opening, preferably one having a straight side and a curved side merging into it. The opening in the flap 8 is indicated at l3, the opening in the flap 9 is indicated at M, and the opening in the side flap I0 is indicated at l5. Opening I5 is deeper than opening l4, and opening H in turn is deeper than opening [3, for reasons hereinafter set forth. From the upper edge of side flap 10 extends what may be called a comb-flap l 6, the teeth of the comb being indicated at IT. This subsidiary comb-flap is to be turned down along the fold line l8 to the position most clearly shown perhaps in Figs. 2, 4 and 5. In the Fig. lembodiment the comb-flap I6 is first turned down on the horizontal fold line l8 and held against the surface of the main part of the flap I as by means of adhesive IS, the adhesive area being as shown in Fig. 1, and the teeth I! being free from adhesive. The side flap I0 is now turned in on the fold line 20 to the Fig. 5 position fiat against the body portion 1 of the blank. Next, the side flap 9 is turned in on the fold line 2| against and overlying the side flap l0. Next, the bottom flap 8 is turned up along the fold line 22 to lie against the side flap 'l. The openings l3, l4 and I5 are so disposed that when all of this'folding has taken place the straight edges of the openings will be in line, and the curved edges 23, 24 and 25 will be as shown in Fig. 4, that is to say, the edge 23 will be higher than the edge 24, and. the edge 24 will be higher which does not become visible unless and until' it is subjected to heat and/or moisture, as in the case of surreptitious steaming, in which event the colored spot becomes visible at the outside of the envelope. The purpose of the particular arrangement of the openings 23, 24 and 25, and the progressive changes in the sizes thereof, will be evident from an inspection of Fig. 4, .where the sealing tongue 28 is shown entered into the opening defined by the aligned openings I3, 14 and I5. It will be evident that because of the step-down arrangement of the curved-edges 23., 24 and 25 of the said openings, the lower edge-of the tongue 28 is not apt to make contact with more than one thickness of envelope material at a time, and therefore the entry of the tongue into the interior of the envelope is facilitated.

The purpose of the comb teeth 11 is toafford a tell-tale as stated. The inside surface'of the sealing tongue 28 will be provided with adhesive and thereby when it is entered into the envelope to seal it, theadhesive will engage the teeth N. If after the envelope has been thus sealed, it should be fradulently opened asby steaming, it is almost inevitable that the fragile teeth I 1' or at least some of them will be torn off, leaving evidence of tampering.

The triangles l2, which Will be folded into the interior of the envelope at the corners as the various flaps 8, 9, ill and II are brought toenvelope-forming position in the manner set forth (see particularly Fig, 6), constitute effective barriers or bailies for discouraging attempts to pry :into the envelope by Way of the corners with some small 'tool, e. g., a form of tweezers designed for the purpose.

By reason of the fact that the teeth I! extend downwardly they will offer no impediment to the insertion of a letter or other contents into the envelope, and the tongue of the sealing. flap likewise can readily pass the comb when moving downwardly. The adhesive used on the tongue may be the kind that remains relatively dry and non-sticking until pressure is applied and held "long enough to cause the adhesive to function and continue to function as such.

In the Fig. 5 embodiment the right-hand main fiap, l0 carries a comb-flap l6 which turns inwardly against the inner face of the main flap on a'vertical hinge-line l8, the upper edge portion of the comb-flap provided with adhesive IQ for securing it to the opposed face of the main flap,

I prefer the Fig, 1 relation of main and combfiaps asoffering, in the complete envelope, less likelihood of interference with the insertion of sheets or the like into the envelope past the combflap. In either fonn the adhesive (and this is true wherever in the specification adhesive is called for) may well be of the pressure-sensitive type.

1. An envelope comprising a rectangular body portion, bottom, side, and sealing flaps, one of the side flaps having a down-turned sub-flap with downwardly extending comb-like teeth, the bottom flap and side flaps having openings therethrough registering with each other and with said teeth, and a tongue on the sealing flap adapted to pass through said openings and having adhesive thereon to engage said teeth.

2. The combination of claim 1, wherein the several openings. are of substantially identical width but of, progressively increased height and are so located with respect to the flaps of the closed envelope that the several top edges of the openings lie in 'alinement with each other and the several lower edges of the openings are stepped inwardly and downwardly of the back of the envelope.

OSCAR V. LALONDE, 

